Carbon—carbon bond forming processes mediated by N-heterocyclic carbene organocatalysts have witnessed recent, impressive progress in the discovery of new reaction manifolds and the development of asymmetric processes. (Zeitler, Angew. Chem. Int. Ed., 44:7506-7510, (2005); Johnson, J. S., Angew. Chem. Int. Ed., 43:1326-1328 (2004); Christman, M., Angew. Chem. Int. Ed., 44:2632-2634, (2005); Enders, et al, Acc. Chem. Res., 37:534, (2004)). Notable advances include new chiral triazolium catalysts for enantioselective intermolecular homodimerization of aryl aldehydes (Enders, et al., Angew. Chem. Mt. Ed, 41: 1743 (2002)), intramolecular aldehyde-ketone benzoin cyclizations and intramolecular Stetter reactions, (Kerr, et al., J. Am. Chem. Soc., 124:10298-10299, (2002); Kerr, et al., J. Am. Chem. Soc., 126:8876-8877 (2004); Read de Alaniz, et al., J. Am. Chem. Soc., 127:6284-6289, (2005); Enders, et al., Helv. Chim. Acta, 76:1899-1902, (1996)). Efforts have focused on extending the mechanistic pathways available to the key “Breslow intermediate” formed by the nucelophilic addition of the carbene catalyst to the aldehydes (Breslow, R. J., Am. Chem. Soc., 80: 3719-3725, (1958)). This strategy was applied to the catalytic generation of activated carboxylates (Chow, J. Am. Chem. Soc., 126:8126-8127, (2004); Sohn, et al., Org. Lett., 7:3873-3876, (2005); Reynolds, et al., J. Am. Chem. Soc., 126:9518-9519, (2004); Reynold, et al., J. Am. Chem. Soc., 127:16406-16407, (2005); Chan, et al.; Org. Lett., 7: 905-908, (2005)), and to novel carbon—carbon bond forming processes that proceed via a formal homoenolate intermediate (Sohn, et al., J. Am. Chem. Soc., 126:14370-14371, (2004); Burstein, et al., Angew. Chem. Int. Ed., 43:6205-6208, (2004); He, et al., Org. Lett., 7:3131-3134, (2005)).
A cost-efficient, scalable method for organocatalysis through a N-heterocyclic-carbene catalyzed Diels-Alder reaction would be a significant addition to the array of available annulation chemistries. Furthermore, a process that provided a highly enantioselective organo-catalyzed intermolecular cross-coupling reaction would be operationally friendly and would not require heating, cooling, complex workup or the use of other reagents. The current invention addresses this and other needs.